The invention relates to a solenoid valve comprising an electromagnet having a coil with an associated yoke means and furthermore a clapper armature for the operation of at least one closing valve member, and a valve housing bearing the coil, said housing having a valve chamber containing the clapper armature with the closing valve member, into which valve chamber an installation opening for the clapper armature is directed, said installation opening being aligned as an extension of the clapper armature and being closed in a sealing manner.
In the case of a solenoid valve disclosed in the European patent publication 1 172 592 A2 of this type the clapper armature is seated on two yoke pins extending through the valve chamber of a frame-like yoke means. During assembly the clapper armature is inserted through an initially open installation opening into the valve chamber, following which the installation opening is sealed off by a plug-like closure part.
This known solenoid valve comprises a relatively large number of parts, something which entails relatively expensive manufacture.
In the case of a solenoid valve also fitted with a clapper armature in accordance with the German patent publication 19,718,408 A1 the valve chamber containing the clapper armature possesses a longitudinal installation opening, which following the insertion of the clapper armature is sealed off by placing a subassembly thereon comprising a coil with a coil carrier, yoke means and a casing housing. For this purpose complex steps must be taken in order to seal off the valve chamber at the installation opening. Since the valve chamber here extends alongside the clapper armature, this part is furthermore not available for making any valve openings desired. If a plurality of valve openings are to be controlled by the clapper armature, they may accordingly only be provided on the longitudinal side, opposite to the installation opening, of the valve chamber.
One object of the invention is to provide a solenoid valve of the type initially mentioned permitting a reduction in the number of components.
In order to achieve these and/or other objects appearing from the present specification, claims and drawings, in the present invention the installation opening is directly closed by a section of the yoke means, the clapper armature bearing in a pivoting manner at the rear on this closure section.
The arrangement of the installation opening as an extension of the clapper armature therefore furthermore renders possible having an installation opening with a small cross section, through which the clapper armature is inserted during its installation in the longitudinal direction. Moreover, this alignment of the installation opening makes possible the provision, if desired, of valve openings on either side of the clapper armature in the wall of the valve chamber. It is more particularly advantageous however that for closing the installation opening no separate closure element is necessary, and instead the yoke means may itself be employed for this purpose by so designing and arranging it that it seals off the installation opening with a closure section thereof. The yoke means is accordingly multi-functional in design and assumes simultaneously a sealing function for the valve chamber in addition to its return function for the magnetic field. It is in this manner that the number of components of the solenoid valve may be reduced.
Further advantageous developments of the invention are defined in the claims.
The yoke means is preferably so designed that it covers over the installation opening like a lid at its closure section. The closure section may be designed like a plate.
For sealing off the installation opening it is preferred to provide a seal placed between the valve housing and the closure section so as to surround the installation opening like a frame. Preferably, the seal is laid in a groove-like recess in the valve housing.
The closure body able to be actuated by the clapper armature is preferably located on the front end, opposite the closure section, of the clapper armature. The closing valve member may be a component permanently connected with the clapper armature or preferably a separate component.
During operation the clapper armature may be switched over between a switching position, in which it is attracted by a stationary solenoid armature part and a further switching position pivoted away from the stationary solenoid armature part. It is convenient for the clapper armature to be constantly urged by a spring means, located in the valve chamber, toward the switching position in which it is pivoted back. For pivoting it toward the stationary armature part and accordingly for switching over into the attracted switching position the coil is excited.
It is an advantage if the clapper armature is made oblique on the rear side so that in the pivoted back switching position it has its rear end face in contact with the closure section over the full area. Accordingly the magnetic field may pass from the yoke means to the clapper armature with a high density and free of loss, something which ensures high switching forces.
It is convenient for the clapper armature to be pressed by spring means against the closure section. The spring means also ensure that the clapper armature remains engaged with a pivot point during the switching over movement, such point being located in the transitional zone between the closure section and the valve housing.
In the case of the closure section it is best a question of a section of a bow-like yoke part fitting around the coil.
For the supply of the necessary electrical actuating signals the solenoid valve is conveniently fitted with a printed circuit board, which possesses suitable connection contacts. The electrical connection between the printed circuit board and the coil is produced preferably by the provision on the valve housing of at least two electrical contact lugs, which are spaced apart, and are electrically connected with the coil, between which lugs the printed circuit board is located, the printed circuit board possessing electrical contact areas at its edge for the other contact areas to rest against. It is in this manner that there is a simply releasable plug connection, which renders possible a simple substitution of the printed circuit board, when the solenoid valve is to be modified for a different operating voltage.
The coil and any printed circuit board are preferably accommodated and protected in a hood mounted on the valve housing with the hood""s opening directed forward. This hood constitutes a sort of further housing in addition to the valve housing. There is the possibility of providing a plurality of hoods, each with particular printed circuit boards for fitting a solenoid valve, which may be selectively employed more especially in a manner dependent on the operating voltage for the respectively used coil.
Further advantageous developments and convenient forms of the invention will be understood from the following detailed descriptive disclosure of embodiments thereof in conjunction with the accompanying drawings.